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to close up; to shut up (e.g. behind doors)
to cut off (e.g. because a deadline has expired); to close off (e.g. subscription list)
雨戸を全部閉切って台風に備えた。
I shut all the storm shutters to prepare for the typhoon.
部屋を閉切ると空気が悪くなる。
The air gets stale when you shut the room up tight.
カーテンを閉切って映画を観た。
I drew all the curtains closed and watched a movie.